Contemporary people usually lead a busy lifestyle lack of physical exercise. As the oil price gets higher and the environmental awareness grows, more and more people turn to bicycles for short distance transportation in addition to conventional recreational or health purpose in order to reduce the energy consumption and carbon-dioxide production.
To provide warning or lighting, most bicycles use a fixed frame and a lighting device. The fixed frame is for fixing a lighting device to the appropriate location on a bicycle, such as the frame, the handle, the back of the seat, and so on. The lighting device provides different lighting conditions, such as blinking, continuous lighting or different color lights for warning or lighting purposes. However, once turned on, the conventional lighting device usually stays in the default lighting condition; thus, lack of interactive or meaningful effects. In addition, when the biker forgets to turn off the lighting device, the battery could use up all the power. Therefore, it is imperative to devise a lighting device that allows interactive warning effects to improve the safety for bicycle riding.